Mercurial > lbo > hg > geohub

<html>
    <head>
        <title>GeoHub :: Track me!</title>

        <style>
        table, th, td {
          border: 1px solid black;
        }
        </style>

    </head>

    <body>
    <!-- My name: assets/trackme.html -->

    <p style='color: red;'>Warning: This website sends your current location to its server (<span id="uiHost">unknown</span>)</p>

    <input type="button" value="Start logging!" onclick="startLogging()" id='uiStartButton' />

    <table>
        <tr>
            <th>Property</th>
            <th>Value</th>
        </tr>
        <tr>
            <td>Status</td>
            <td id='tblStatus'>?</td>
        </tr>
        <tr>
            <td>Last time</td>
            <td id='tblTime'>?</td>
        </tr>
        <tr>
            <td>Latitude</td>
            <td id='tblLat'>?</td>
        </tr>
        <tr>
            <td>Longitude</td>
            <td id='tblLong'>?</td>
        </tr>
    </table>

    <script>

    var urlParams = new URLSearchParams(window.location.search);
    var url = new URL(window.location);
    var secret = urlParams.get('secret');
    var client = urlParams.get('client');

    // Tell the user where their data is going.
    document.getElementById('uiHost').textContent = url.hostname;

    secret = secret ? secret : '';

    var trackUrl = url.origin + url.pathname;
    // Maybe just use relative path?
    trackUrl = trackUrl.replace('assets/trackme.html', `${client}/log?secret=${secret}`);

    function updateUITable(pos) {
        var coord = pos.coords;
        var lastTime = new Date(pos.timestamp);

        document.getElementById('tblTime').textContent = lastTime.toTimeString();
        document.getElementById('tblLat').textContent = coord.latitude.toString();
        document.getElementById('tblLong').textContent = coord.longitude.toString();
        document.getElementById('tblStatus').textContent = 'Acquired';
    }
    function updateUITableSetLogged() {
        document.getElementById('tblStatus').textContent = 'Logged';
    }

    function xhrLogCallback(xhr, readyStateChange) {
        if (xhr.readyState === XMLHttpRequest.DONE) {
            if (xhr.status == 200) {
                console.log('Location update successful.');
                updateUITableSetLogged();
            } else if (xhr.status == 400) {
                console.log('Location update unsuccessful! Status:', xhr.responseText);
            }
        }
    }

    // Returns closure f(GeolocationCoordinates) logging to this Geohub.
    function getLoggingHandler() {
        var lastLat = 0;
        var lastLong = 0;
        return function(glp) {
            var glc = glp.coords;
            if (client == null) {
                console.log('Not logging: Client is null!');
                return;
            }
            if (glc.latitude == lastLat && glc.longitude == lastLong) {
                console.log('Not logging: Position has not changed');
                return;
            }

            updateUITable(glp);

            lastLat = glc.latitude;
            lastLong = glc.longitude;

            const speedorempty = glc.speed ? `s=${glc.speed}` : '';
            const elevationorempty = glc.altitude ? `ele=${glc.altitude}` : '';
            const accorempty = glc.accuracy ? `accuracy=${glc.accuracy}` : '';
            var querystring = `&lat=${glc.latitude}&longitude=${glc.longitude}&${speedorempty}&${elevationorempty}&${accorempty}`;
            var url = trackUrl+querystring;

            var xhr = new XMLHttpRequest();
            xhr.responseType = 'json';
            xhr.open('POST', url, true);
            xhr.onreadystatechange = function(result) { xhrLogCallback(xhr, result); };
            xhr.send();
        };
    }

    const loggingHandler = getLoggingHandler();

    function locationUpdate(pos) {
        console.log('new location:', pos);
        loggingHandler(pos);
    }

    function startLogging() {
        var geo = navigator.geolocation;
        geo.getCurrentPosition(locationUpdate);
        var watchId = geo.watchPosition(locationUpdate);

        document.getElementById('uiStartButton').value = 'Stop logging!';
        document.getElementById('uiStartButton').onclick = function() {
            geo.clearWatch(watchId);
            document.getElementById('uiStartButton').value = 'Start logging!';
            document.getElementById('uiStartButton').onclick = startLogging;
        };
    }

    </script>

    </body>
</html>
author	Lewin Bormann <lbo@spheniscida.de>
date	Fri, 04 Dec 2020 11:18:48 +0100
parents	5074024fc84d
children	45d88bf5d99f